Railway cars, such as tank and freight cars, typically include one or more railway truck assemblies that support one or more pairs of wheels on an axle. The railway truck assemblies include a frame that supports the axle via a bearing pad mounted in an axle mounting bracket. The railway cars are used in severe weather such as snow and ice and accumulate debris. As a result, ice and snow accumulate on the bearing pad, axles and wheels and deteriorate performance of the railway car. Accordingly, the railway cars are subject to de-icing and cleaning procedures that include spraying the railway car, the railway truck assemblies, wheels, axles and bearing pads with cleaning agents and de-icing agents. These cleaning agents and de-icing agents are corrosive. In addition, to thaw the ice and snow accumulated on the railway cars, the railway car, the railway truck assemblies, wheels, axles and/or bearing pads are heated to temperatures up to 350° F., for example, in a railway car ovens.
In order to survive the de-icing, cleaning and thawing operations and to support heavy loads imparted by materials contained in the railway cars, the bearing pads are typically made from a metallic material. However, such metallic bearing pads require a lubricant (e.g., grease) applied thereto to prevent premature wear and failure caused by operation of the railway cars at high speeds while carrying heavy loads and the resultant oscillatory movement between the bearing pads, the axle mounting bracket and the frame. However, the lubricant can become washed out during cleaning, de-icing and heating operations. If the bearing pad was not lubricated, high friction levels result in the inability of the railway car from being able to translate and can increase the propensity for the car to roll over. As a result, frequent maintenance is required to replenish the lubricant.
Attempts have been made to use a self-lubricating material for the bearing pad. However, such self-lubrication materials are generally polymer based and cannot withstand heating to 350° F. and tend to crush, creep, extrude or cold flow under high loads and high temperatures.